Included in the mandate for the next generation of cooperative group efforts is the need to extend prior POG studies, as well as those from other institutions and groups, on the nature and classification of tumor biology and to expand such efforts into feasible phase II/III studies. Histologic, immunologic and natural history classifications of acute lymphoblastic leukemia have enabled investigators to develop therapeutic efforts tailored to address specific entities in this regard, i.e., high risk (WBC greater than 50,000/mm., T-cell), low risk, occult disease, extramedullary relapse. For certain categories and subclassifications, it is apparent that such therapeutic efforts have resulted in dramatic improvement, as in Wilms' tumor and rhabdomysarcoma; in others, the results have been disappointing, i.e., Ewing's sarcoma, stage III/IV neuroblastoma, brain tumors, osteogenic sarcoma, high risk ALL, and AML. Pharmacokinetic studies of megadose therapy and data derived from transplantation biology and related phase II studies provides opportunities heretofore not readily available to employ high-dosage regimens with temporal monitoring of drug kinetics so as to utilize pharmacologic rescue regimens, as in high dose MTX with folinic acid rescue, or marrow infusion following ablative therapy. The bone marrow transplant unit at the University of Florida will continue (1) to conduct allogeneic transplantation studies of high risk ALL, and AML, in first remission designed to ask questions concerning conditioning regimens and immune recovery, and (2) to utilize autologous marrow rescue following megadose therapy coupled with pharmacokinetic data for relapsing/resistant solid tumors, i.e., Ewing's sarcoma, neuroblastoma, non-Hodgkin's lymphoma, brain tumor, Hodgkin's Disease and Wilms' tumor. Research endeavors will include correlating histologic and immunologic characteristics with therapy responses as in ALL and neuroblastomas. Whole group endeavors will consist of active participation in ongoing and newly developed protocols including a multi-institution osteogenic sarcoma study. Efforts have also been rewarding in scientifically involved investigation including surgeons and radiotherapists as well as identifying additional satellites representing a further accrual of 35-40 patients/year, establishing a rural referral for maintaining home care and medical center communication, and establishing a comprehensive psychosocial support system.